.500 ball in .50cal. Greenmountain

[sparsons]

Went up to Cains today to pick up some roundballs. They were out of .495 so I opted for .500 balls. Scott told me I would be wanting to move up to the .500 anyway since Greenmountain barrels seem to run a little larger than most barrels. I will be using Walmart pillow ticking with 75 grains of fff Goex along with the .500 roundball. Any of you guys tried this combo or am I nuts for trying? Going shooting tomorrow afternoon. :grin:

 

[Dave Rosenthal]

Bring a hammer and an assortment of different thickness patches...and a ball puller as a last resort!

Hope that you don't incur any problems...but remember a really thin patch sometimes can't do all we ask of it!

Have fun and enjoy the day shooting!!

Dave

 

[Rifleball36]

Bore size ball is the way to go with the GM. barrel. I shoot a .360 ball in the GM. .36 cal barrel with .015 patch. I tried the .350 ball and thicker patch but it would not shoot as good. My 36cal. was .362 size. With the .360 ball and .015 patch I was able to put 4 of 5 shots in a 1" group at 100 yds. off bench the other day. It was the best groop I have ever had. I must have done something right for once. With the bore size ball the loading is a little tight to get started but goes down easy. I think you will like the .500 balls, but you may have to drop down to a .015 thick patch

 

[jimeckersley]

My Green Mountain Barrels have wide grooves and narrow lands. This makes them a little more forgiving when loading a bore size ball. It has the effect of a larger bore diameter but still holds the patch very well, even with large powder charges.

Another barrel maker that uses this narrow land wide groove system is Bill Moody.

If the grooves are narrow and lands are wide, be sure to take a hammer to the range along with a good range rod.

 

[squirejohn]

I used to shoot a .500 ball, teflon coated patch,and 90g of 2f in a drop-in GMB for a TC Hawken. A mallet and range rod was needed to load it. I could never find a smaller ball and/or patch combo that loaded eay an was accurate.
I also have a .45 GMB in which I shoot a .451 ball, .008 patch and 55g of 3f. Since I coned the muxxle I can easily thumb start the load.

 

[sparsons]

Just got in from shooting. The new .500 roundball with the .50 cal. Greenmountain barrel worked great. Used lube on the first ball but after that just spit. I upped the grains to 80 of 3f with the walmart pillow ticking. Grouping was good but I was more surprised at how easy it was to slide the ball down the barrel. :grin:

 

[paulvallandigham]

Sparsons: I am not doubting the result, but i would like to know that you actually have measured those balls and that they really are .500" in diameter. And I would like to know that you measured the actual bore dimensions of that rifle and it measures what you say it is. And it would be nice to know the exact thickness of the Wal Mart pillow ticking that you used, rather than hope that the stuff I find locally is the same thickness that you have.

I hate to be picky,but I have to believe that the barrel is oversized, or the ball is undersize from the advertised dimensions. You should not be able to push a .500 round ball down using pillow ticking as a patch in a .50 caliber barrel and do so easily. I use a .490 ball in my .50, and tried the .495 and found it next to imposslble to seat, evne after using .010" patches.

 

[shmrck1]

Paul,
Thanks for that reply. I was thinking it was just me having the same thoughts.:hmm:
snake-eyes:hatsoff:

 

[MikeChapin]

I have three rifles with Green Mountain barrels. I use a .024 denim patch in all of them. All load with a slap on the short starter and go down smoothly after that.

The .50 barrel is about 20 years old and has seen a lot of use. I use a .490 ball. I could probably use a .495 with a .015 or .018 patch easily enough. I would doubt if I could get a .500 ball down there without a three pound sledge.

The .32 is about the same. It takes a .311 ball with the thicker patch easily enough. a .315 would probably do allright with a thinner patch also. I can't imagine trying to get a .32 ball down with anything as a patch.

The .58 is about the same. I use a .562 ball with the denim. I have used a .570 with a .020 and .018 patches. It loads a little tighter than the combo I use now but shoots about the same. I could probably load a .575 with a .010 patch but would probably have burn through even with the light loads I use.

I would say try it out. I'm not a big advocate of using a hammer to start and load but some people swear by it and some of them do quite well.

 

[sparsons]

No I didn't measure this particular bunch of balls. I have measured Cain's standard roundballs in the past and they tend to run up and down the scale. As far as the bore goes all I know is what I have been told and that is the Greenmountains tend to run on the high side. I started the ball with a starter after which it went down smoothly with a range rod. I did dry ball once :cursing:. After removing the nipple adding powder I fired into the ground. My buddy and I recovered the ball and it was in very good shape. Slight imprint of the ball starter around the spru. I have been shooting black powder not yet two years so that is why I threw out the question. To me a .50 ball in a .50 barrel plus the patch equals a square peg in a round hole. But as I said. Cain's explained to me when I bought the barrel that Greenmountains due to their contrtuction on the lands and grooves tend to run on the high side. The pillow ticking I have here now mics out at .013. Some guys swear that it is .018 but I have yet to find it that thick.

 

[paulvallandigham]

Well, how about taking the mystery out of that barrel for all of us, and measure it? Then report your findings here. If you don't own a caliper, then borrow one, or ask a local machine shop to measure the bore, both lands( bore diameter) and groove diameter. Take a couple of lead balls with you and have them use a micrometer on them to give you an idea as to what they are, instead of what they say they are! Let us know.

I am shooting a GM barrel on my .50, made 25 years ago or more. My land diameter( bore diameter) is .500, and my groove diameter is .512". Green Mountain makes a lot of barrels. I just can't see them making oversized bores without some industrial based reason. I shoot the .490 ball, with a .015 patch. The lube is NL1000, a/k/a Wonder lube, Bore Butter, etc. I have been shooting Hornady swaged balls for years because of their consistent roundness, weight, and dimension.

Much of my shooting was done doing shooting demonstrations at my gun club's activities, and when folks learned that I could cut playing cards consistently, or shoot out candle flames, or split a ball on an axe blade and break two targets, one on each side of the blade, I was " in demand " as they say. I got very fussy about the balls I shot so I did not let down the club, or embarrass myself in front of audiences.

see my article on Trick shooting:
[url] www.chuckhawks.com/off-hand_shooting.htm[/url]

I hope that helps. And I really would like to now how that barrel measures.

Paul

 

[Smk50]

I was using .490 in my GM barrel and it was accurate, but I thought I could do a little better. Last weekend we camped at our range for our spring shoot so I had plenty of time to dink with loads and such. I went to a .495 ball and had .020 cotton patches, Rifle definitely likes the new combo, I also had my standard PT patches and also .010 , .015, bu tit likes the .020 and .495 balls. They do load a little stiff, a couple good smacks to the short starter and they are in(though my hand hurt at the end of the day) but they slide down reasonably easy. 35 gr 3f goex for targets worked well at 25 yds, from bench I shot four 3 shot groups that could be covered with a quarter, at 50 yds with 50 gr 3f goex groups opened up to 1 1/2 - 2inches. at 100 yds I dont know but same load I was able to break 6 balloons that were about 6 inches in diameter. I am happy so far, but I dont know that id try the .500 balls to me that sounds liketrying to stuff too much in th ehole.

 

[sparsons]

Paul, used my mic. not sure how accurate it really is but I am coming up with the bore being at .5156. I put the mic. in several different spots around the inside.

 

[paulvallandigham]

Based on my barrel, I suspect that you are measuring the groove diameter, and not the lands. The land are the high spots in the barrel.

When you measure a spent bullet the grooves in the bullet are left there by the lands, and the high spots on the barrel represent the wider groove diameter. Everything is opposite from what is in the barrel. A barrel is first drilled and bored and then polished to a smooth surface, before a cutter cuts the groove in the barrel. What is left we call the Lands of the riflling, and they are the " Bore diameter". On my rifle the lands are not much wider than the jaws of my inside calipers, so it took some careful handwork to get the proper measurement.

Perhaps that is why we are not communicating well.

Put that mike on some balls and tell us the diameter you get on them.

 

[sparsons]

Paul, went back and measured the bore again. This time making sure I was on the lands and it came back the same. I measure about a third of the roundballs and as I suppected they run up and down the scale. Most were just shy of a true .500 but some were right on the money. I have shot .495 Hornady's through it and may try a box of them as they tend to run much truer to size. I have read that article you wrote in fact I have it bookmarked so that I can go back and read it to refresh my memory (its an age thing). When I have a bad day shooting I usually return there when I get some just to see what I did wrong.

 

[squirejohn]

Sparsons, FWIW the land and groove diameter of the GMB I mentioned above measured .501, & .521.
I had purchased the barrel through MT State Muzzleloading in which Ed Cains was co-owner. In the front of their catalog they said in reference to the .50 Gmb that, GMB recommends a .495 ball for hunting and a .500 ball for target shooting.

 

[paulvallandigham]

Sparsons, thanks for that added information. Your barrel is not much different than mine, as far as bore size. I would try a .495 ball and a .015- .018" thick patch, lubed, of course, in that gun and see how it shoots. You should get excellent accuracy, and not have to fight to seat the ball, or distort the ball in the process. The .495 ball will give you about .020" of room for a patch, but you have to remember that the patch is on both sides of the ball, so its really .010 on each side of that ball. And, because the lands are .501, the patch fabric over the lands is goind to be compressed and needs to go somewhere, and that somewhere is into the grooves. If the .015 is too thick, then move down to .012, or .010.

With a load of 80 grains of FFFg powder, some shooters are finding that the patch is burned, or torn and gase cuts the ball, ruining accuracy. Use a wad on top of the powder, or a filler to seal those gases to protect those thinner patches. As long as your rifling doesn't have burrs on the lands, it should not cut even the .010 lubed patches loading or shooting the gun. Let those thin patches do their primary job, and that is to grab the ball and the rifling and tranfer the twist of the rifling to the ball when the gun is fired. The secondary job of the patch is to lube the barrel to keep fouling soft after the ball passes. The third job for the patch is to seal the bore from gases behind the ball escaping up the rifling. Those hot gases will tear the thin patches( thick ones, too) and gase cut the soft lead.

I believe those three jobs are an awful lot to ask a thin patch of cloth to do. I use wads and fillers to seal the gases, and I run a lubed cleaning patch down the barrel AFTER seating the PRB on the powder to lube the barrel. The lube in the patch just provides something to reduce the friction between the patch and the barrel at ignition. The patch is asked to do only one thing, and that is to transfer the twist of the rifling to my round ball so that it is spinning when it leaves the barrel.

Good shooting.